Meet Leslie Caldwell. President Obama has installed Ms. Caldwell, known as a "terror of a prosecutor," as head of the Criminal Division of the Department of Justice. It has been over a decade since Ms. Caldwell destroyed Arthur Anderson, and with it, 85,000 jobs—only to be reversed by the Supreme Court nine to nothing (well after she went into private practice). Now the president has brought her back—with a big promotion—and the vengeance of DOJ already aimed at Credit Suisse, BNP Paribas and others.

Ms. Caldwell and her then right hand man, Andrew Weissmann, viewed businessmen and bankers as "wise guys on Wall Street," deserving of brutal prosecutorial tactics. Their prosecutions proceeded on the theory that the "end justifies the means." Winning was the sole goal. They forgot that the job of a federal prosecutor is to seek justice—not convictions.